Viruses are a significant cause of human cancer and are an even more common cause of cancer in immune deficient humans such as organ transplant recipients or HIV infected people. Analyses of the way viruses alter cell growth has also frequently led to the delineation of novel pathways of cell growth, cell survival and oncogenicity. This Viral Oncology Training Program will provide support for 2 graduate students for G2 or G3 years and for 5 post-doctoral trainees each year for the laboratories of 16 Viral Oncology Program faculty members at Harvard University and its closely affiliated institutions. The research objectives of these laboratories include: (1) Molecular pathogenesis of Human Papillomavirus induced malignancies including cervical, anogenital and oral cancer. (2) Molecular pathogenesis human and primate gamma herpes virus induced malignancies including lymphoproliferative disease and nasopharyngeal carcinoma. (3) Molecular mechanisms by which small DMA tumor viruses including Papovaviruses and Adenoviruses alter cell growth and survival. (4) Molecular mechanisms by which RNA tumor viruses infect and alter cell signal transduction, transcription, cell cycle regulation, and cell survival, and (5) Translational research in areas 1 and 2 including therapeutic target identification, target validation, small molecule screens, and experimental models, as well as programmatic objectives that emerge through interactions with disease and population based investigators. Graduate students engage in viral oncology laboratory research training while pursue 3 semesters of course work in molecular biology, genetics, cell biology, virology and immunology. The course work is based in reading of research papers and proposal writing. By January of year 2, students are in full time mentored thesis research. Post-doctoral fellows engage full time in mentored research training. Pre- and post-doctoral students also participate in seminars, journal clubs, and research conferences including conferences of the Virology Program and of the DF/HCC Viral Oncology Program. Trainees are jointly mentored by research trainer and by other program faculty. On completion of their thesis research pre-doctoral students are prepared for postdoctoral research in viral oncology and related disciplines. Postdoctoral trainees are prepared for independent research in viral oncology and related disciplines. This application has been revised to comply with suggestions made in the previous review.